Structure-activity relationship of antioxidant polysaccharides from Salvia miltiorrhiza based on multiple fingerprint profiles and chemometrics analysis

The polysaccharides of Salvia miltiorrhiza (SMP) from 10 different sources were obtained by water extraction and alcohol precipitation, and their physicochemical properties and structures were analyzed. Multidimensional fingerprints based on high-performance liquid chromatography (HPLC), high-performance gel permeation chromatography (HPGPC) and proton nuclear magnetic resonance (1H-NMR) were established, and monosaccharide composition (galactose, glucose), molecular weight (SP1 2.07 × 106 Da-5.57 × 106 Da, SP3 692.20 Da–707.22 Da) and chemical shift (δ2 4.982 ppm, δ4 5.317 ppm) could be used for the quality control of SMP. The antioxidant activity was evaluated, and the spectrum effect relationship was studied. Galactose in the monosaccharide composition and the 2.07 × 106 Da-5.57 × 106 Da component in molecular weight were found to have a positive correlation effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, which can provide a preliminary basis and data reference for the quality control and structure-activity relationship study of SMP.